Sizing of cellulose ether and ester materials



Patented Mar. 5, 1940 UNITEDSTATES QFFICE ziisiar a No Drawings.

This invention relates to the treatment of cellulose ether and estermaterials and more particularly to the sizing of cellulose acetatematerials prior to weaving.

The sizing of certain textile materials with starch or starchderivatives presents special" problems, particularly in the sizing ofregenerated cellulose and cellulose ether and ester materials. Thus, insizing regenerated cellulose an ordinary starch size adheresso well tothe ma terial that a distinct problem is encountered in I, desizing thematerial after weaving. In otherf words, there appears to be a bond orafllnity between a, starch size and a regenerated cellulose; On theother hand, fibers such as the wellknown cellulose acetate when sizedwith ordinary amylaceous sizing compositions fail to weave properly, thesize being rapidly removedv from. the fibers under the chafing action ofweaving. For 0 this reason it has not been possible to satisfactorilysize cellulose ester yarns such as cellulose acetate with amylaceousproducts, and it has been necessary to rely entirely .upon specialsizes, particularly sizes of a protein nature such 25 as gelatin. caseinand the.like.

It is an object of this invention to provide a method of sizingcellulose acetate and other cellulose ester or cellulose ether materialsutilizing amylaceous materials. A further object is the 30 preparationof improved cellulose acetate sizing compositions. Another object is toprepare cellulose ecetate sized with a composition which strengthens thefibers to resist the mechanical action of the loom and is not rapidlyremoved 35 under the chafing action of weaving. Other objects willappear hereinafter.

These objects are accomplished in accordance with this invention byincorporating about to or more of urea in a specially prepared m starchderivative and applying the resultant composition as a sizingcomposition to cellulose ester or ether fibers, particularly celluloseacttate. I have found that such a sizing composition becomes bound tocellulose acetate fibers,

45 that is, it shows a natural afilnity previouslylacking. The exactnature of this action is unknown, but it seems to be due to somecoordinate valence bonding between the starch on the one hand and thecellulose ester on the other. 50 Good results can be obtained withcompositions containing a minor proportion of urea and a majorproportion of a dispersible amylaceous material, the amount of ureapreferably being about 25% to 75% by weight of the amylaceous 55'material.

Application June 14, 1937, erlal No. 148,113

9' Claims. (01. 1344-23) g The manner in which the invention may bepracticed wlll'be illustrated, but is not limited, by the followingexample in which the quantities are stated in parts by weight:

Eeample 'A sizing composition was prepared by mixing together 10-partsof a modified starch, 2 to 6 parts of urea, "and '40 to 80 parts ofwater,-and heating the mixture at atemperature of about 10 180? withagitation for 15 minutes.

A cellulose: 'acetatecyarn was then sized by -'the skein "method'by:immersing it in the resultant sizing composition -at-.a temperature ofabout 140 to ab0ut .150 F. Ifdesired, the sizing may 5 be efieete'dinthe cold at temperatures of say 60" t0'80 F.

--Thesize strengthened the fibers to resist the mechanical action" ofthe loom'and was not rapidly removedunder the chafing action of weav- 20ing; After weaving'thesize was readily removable by washing with water.

In the above example auxiliary agents may be added-to the composition,for instance, 1.5 parts of glycerine or 3 parts of Turkey red. This 25form'ulacan be used for both skein and warp sizing. I

In a similar manner other compositions may be prepared in'accordancewith the invention, with varying-proportions of urea and amylaceousmatter. It is usually preferable to employ a starch degenerationproduct, by which is meant a derivative of starch such as may beobtained by the various processes of making thin-boiling and so-calledsoluble starches and dextrins. By a specially modified starch is meant astarch degeneration product which, after having been colloidallydispersed in water, yields a dried protective film of suitable physicalcharacteristics for the purpose involved. In order to obtain thesecharacteristics and to form so-called solutions suitable for textileapplication, ordinary undegenerated starch is suitably degenerated inpart, or modified, by various chemical and heat treatments. If desired,.mixtures of undegenerated starch and modifled starches may be used inconjunction with the urea. A

The term amylaceous material is employed herein to cover starch andstarch derivatives or degeneration products. The expression "starchdegeneration products" is employed to cover dextrins as well as modifiedstarches. Among the suitable starchy materials may be mentioned wheat,rye, barley, oat, rice, maize and potato starches, sago and cassavaflours and starch dato use a sizing composition having a ratio of solidsto water within the range of about 2:5 to about 1:7.

The amount of such material incorporated into or applied to thecellulose acetate-is subject to variation, but ordinarily good resultsare obtained by adding to the cellulose acetate about 4% to about 6% ofthe sizing composition based upon the normally air-dry weight of thesized material. The amount of sizing composition retained by thematerial treated will depend largely upon the concentration of the bathand the time of treatment. Ordinarily the bath may be either hot orcold. The method of treatment may be the warp method, skein method orany other suitable method.

It will be recognized that a wide variety of auxiliary agents may beadded to the sizing compositions herein described. Among such additionagents may be mentioned fullers earth, bentonite; wetting, penetratingand dispersing agents, for example, sulfonated oils,'higher alcoholsulfates (e. g., dodecyl sulfate, cetyl sulfate, and similar compounds),dlethylene glycol, glycerine and related substances. The proportions ofthese materials may also vary, depending upon the type of treatment andthe material treated. For instance, it is usually preferable to useabout 2 parts of glycerine or 4 parts of Turkey red oil for each 80parts of sizing composition in the treatment of cellulose acetatematerials. It will be observed that applicant's compositions are of sucha nature as to be permanently water dispersible even upon theapplication of heat.

In preparing the sizing compositions described above it is preferable toprepare a dry blend of amylaceous binding agent and urea as a basematerial. This blend is marketed in dry or powdered form and requiresonly the addition of water and mixing, preferably with heating, toproduce the sizing composition. Auxiliary materials such as thosementioned above may also be included in the dry base.

It will be apparent that the use of an amylaceous material intimatelydispersed with urea in sizing textile fibers such as cellulose acetatehas many advantages over the use of the amylaceous substance or urea perse. starchy materials .alone have not proven satisfactory in celluloseacetate sizing because of the lack of afiinlty with cellulose acetate.Urea has been suggested for use in conjunction with starch and othermaterials in veneer glues but has not heretofore been applied to starchsizing mixtures for cellulose acetate and similar materials. Ureasolutions have also been used to reduce the infiammability of materials,but the use of urea alone does not fulfill the function of thecombination of urea and starch or starch degeneration products for thetreatment of cellulose acetate and similar materials as hereindescribed.

Having thus described the invention, what I claim as new "and desire tosecureby Letters Patent of the United States is:

1. In the art of sizing cellulose ether and ester materials, the stepwhich comprises applying to said materials a permanently waterdispersible composition containing an intimate dispersion of anamylaceous substance and urea, the amount of urea being at least about20% by weight of the amylaceous substance.

A method of sizing cellulose acetate yarn which comprises treating theyarn with a permanently water dispersible intimate dispersion of anamylaceous substance and urea in water, the amount of urea being atleast about by weight of the amylaceous substance and the ratio ofsolids to water being within the range of about 2:5 to about 1:7.

3- A method of sizing cellulose acetate yarn which consists in treatingthe yarn with an intimate dispersion consisting essentially of about 10parts of a modified starch, 2 to 6 parts of urea and 40 to 80 parts ofwater.

4. A cellulose acetate sizing composition com-' prising a permanentlywater dispersible intimate dispersion of an amylaceous substance andurea in water:

A cellulose acetate sizing composition-comprising a permanently waterdispersible intimate dispersion of a starch degeneration product andmain water, the amount of urea being about 25% to about 75% by weight ofthe starch degeneration product and the ratio of solids to water beingwithin the range of about 2:5 to about 1':'7. 6. A sizing compositionadapted for sizing cellulose acetate fibers prior to weaving andconsisting essentially of an intimate dispersion of about parts of amodified starch and about 2 to about 6 parts of urea in about 40 toabout 80 parts of water.

'I. A cellulose ether and ester material sized with a permanently waterdispersible intimate dispersion of an amylaceous substance and urea inwater.

A cellulose acetate material containing a sizing composition consistingessentially of a major proportion of amylaceous substance and a minorproportion of urea, the amount of urea being at least 25% by weight ofthe amylaceous substance.

9. A cellulose acetate material containing a permanently waterdispersible sizing composition having an amylaceous material as its soleor substantially its sole binding agent and containing urea in an amountfrom about 25% to about 75% by weight of the amylaceous material.

HERMAN B. BOSLAND.

CERTIFICATE OF CORRECTION.-

Patent No. 2, 19?,219. March 5, l9lLO.

HERMAN s. B0sLA1 rD. It is hereby certified that error appears in theprinted specification of the shore numbered patent requiring correctionas follows: Page 1, first column, line 52, for "acetate" r'ead acetate;and second column, line 25,

after the word "red" insert oil; and that the said Letters Patent shouldbe read with this correction therein that the same may conform to therecord of the case in the Patent Office Signed and sealed this 9th dayof April, A. D. l9h0.

Henry Van Arsdale,

(Seal) Acting Commissioner of Patents

